1. Field of Invention
This invention pertains to a highway reflector designed and positioned to warn wild animals of approaching vehicles. Properly located warning reflectors are optical means particularly intended to avoid traffic accidents between moving vehicles and wild animals at night. Many serious accidents occur near forested areas when animals such as deer are struck by fast-moving vehicles while crossing unlit highways during night time hours.
2. Description of Prior Art
In U.S. Pat. No. 3,814,500 a deer warning reflector is described consisting basically of a prism plate which is sealed in a housing so that it is watertight. The erection of these warning reflectors for deer have led to a considerable reduction of the number of accidents. These reflectors work on the principle of diverting the light rays from oncoming vehicles by means of internal reflection off of a planar prism. The top surface is curved to disperse the light. These warning reflectors have the disadvantage of consisting of several individual parts which give rise to high production and assembly costs. They also do not allow for variation in light ray reception and reflection by simple adjustment of the optical elements.
In U.S. Pat. No. 4,406,045, a Division of U.S. Pat. No. 4,252,409, another warning deer reflector is described. This reflector has also been shown to be effective in reducing accidents. It is similar to the invention described here in that it consists of transparent plates with certain kinds of toric surfaces. However, to achieve adequate roadside light coverage, two distinctly different types of these reflectors are required, one for flat terrain and another for hilly terrain. This makes manufacturing and installation more complicated and costly because the hilly terrain reflectors have a relatively small horizontal light coverage and need to be installed very close together to be effective. Also, the reflectors are to be installed adjacent to and directed away from the highway rather than directed across the highway. As described below, there are very important advantages to installing warning reflectors with particular reflecting characteristics to direct reflected light across the highway.